Examples of a conventional electronic device include an electromagnetic relay apparatus including a plurality of electromagnetic relays each having a couple of movable contacts that swing by the excitation current flow in a coil and a couple of fixed contacts faced to the movable contacts and set in directions of movement of the movable contacts with the movable contacts set between the fixed contacts. In the electromagnetic relays, one of the movable contacts and one of the fixed contacts form a normally-open contact which is closed when excitation current is applied to the coil, and the other movable contact and the other fixed contact form a normally-closed contact which is closed when current is not passed through the coil. The electromagnetic relays are disposed in line on a base so that the plural normally-open/normally-closed contacts of adjacent electromagnetic relays are faced to each other and located in opposed outer positions in substantially point symmetrical relation with the swing center side of the movable contacts being located outward (refer to Patent Literature 1).
The electromagnetic relay is a bipolar electromagnetic relay in which two sets of electromagnet blocks 1, 1 are incorporated in one housing including a base block 2 and a cover B mounted to the base block 2, as shown in FIGS. 1 and 3 of the Patent Literature 1.